Flat bag and overflapped adhesive tape closure therefor



Jan. 7, 1969 R; BOSTWICK 3,

FLAT BAG AND OVERFLAPPED ADHESIVE TAPE CLOSURE THEREFOR Filed Aug. 7, 1967 INVENTOR R0 RT OSTWICK 3' BY B I I United States Patent ()fiice 3,420,433 Patented Jan. 7, 1969 3,420,433 FLAT BAG AND OVERFLAPPED ADHESIVE TAPE CLOSURE THEREFOR Robert Bostwick, Somerville, N .J., assignor to Union Carbide Corporation, a corporation of New York Filed Aug. 7, 1967, Ser. No. 658,731 US. Cl. 229-80 4 Claims Int. Cl. 365d 33/20; B65d 83/00 ABSTRACT OF THE DISCLOSURE A flat bag of the type used for packaging sandwiches and the like is provided with a closure flap extending from the rear wall and having an adhesive applied thereto for sealing the flap to the front wall of the bag. The closure flap is folded or overflapped upon itself to form a protective enclosure for the adhesive prior to use of the bag. The overflapped closure prevents the adhesive from becoming inadvertently adhered to an exterior object and, in particular, adjacent bags in a dispensing carton.

This invention relates to flat bags of thin flexible sheet material. More particularly, the invention relates to a flat bag of the type used for packaging sandwiches and the like, and to a novel and improved adhesive type closure for sealing the bag.

Background the invention A flat bag as the term is used herein consists essentially of two superimposed front and rear wall members which are joined together at the edges thereof except at one edge which is left open to constitute a bag mouth. Flat bags of this invention are adapted especially for use in packaging sandwiches and other food products, and are preferably made from thin transparent flexible plastic film material.

Bags of this type and especially sandwich bags for packaging freshly prepared sandwiches, pasteries, bread and the like have now become a common item of commerce. 'Because of the perishable nature of the food or other products to be packaged, these bags have usually been provided with a closure for sealing the bags. One type of closure that has been widely used consists of a flap extending from the rear wall of the bag which is adapted to be drawn down over the bag mouth and onto the front wall in order to close the bag. With this type of bag closure, it has become customary to apply an adhesive to the flap for adhering the flap to the front wall of the bag.

While this type of bag closure has proven to be simple and convenient to use, the bags nonetheless have been plagued by certain difficulties. One principal difficulty has been that of packaging the bags within a dispensing carton and particularly one of the type wherein the bags are stacked together or placed adjacent to one another within the carton. With this type of dispensing carton the bags have had a tendency to become adhered to one another through the adhesive and thus it has been difficult to dispense one bag at a time from the carton. Furthermore, dispensed from the carton, the bags may often become inadvertently adhered to some exterior object, thus making it difficult to use the bags.

Summary of the invention The invention proposes to overcome these dilficulties and to generally improve upon the construction of fiat bags of the type provided with a closure flap extending from the rear wall and having an adhesive applied thereto for sealing the flap to the front wall of the bag.

This is accomplished according to the invention by providing the bag with an overfiap closure which protects the adhesive from contact with an exterior object and, in particular, adjacent bags in a dispensing carton. Thus the bag is provided with a closure flap extending from the rear wall and having an adhesive preferably located near the bottom edge of the flap, which adhesive is adapted to secure the flap to the front wall of the bag. In constructing the bag, the flap is folded upon itself in such manner that the adhesive is disposed between overlying portions of the flap and thus protected from becoming adhered to adjacent bags in a dispensing carton and once dispensed from the carton, from becoming inadvertently adhered to an exterior object during use of the bag.

To use the bag, the closure flap is simply separated and then drawn down over the bag mouth and onto the front wall where it is secured by the adhesive.

The novel features, objects, and advantages of the invention will be more clearly understood from the following description of preferred embodiments thereof when read in connection with the accompanying drawing.

Brief description of the drawing FIGURE 1 is an elevational view of a fiat sandwich bag embodying the invention, showing the closure flap partially separated to illustrate its construction in greater detail;

FIGURE 2 is a cross-section view of the bag taken along the lines 22 of FIGURE 1;

FIGURE 3 is a perspective cut-away view of the bag showing a sandwich packaged within the bag and the closure flap secured to the front wall in order to close the bag; and

FIGURE 4 is a perspective, cut-away view of a typical dispensing carton for packaging a number of flat sandwich bags of the invention.

Description 0 the preferred embodiments Although the invention is applicable to a number of different types of flat bags, the novel features and advantages thereof are particularly useful in flat sandwich bags of the type used for packaging freshly prepared sandwiches, pastries, bread and other food products. With this in mind, the preferred embodiments of the invention will now be described in connection with the flat sandwich bag illustrated in the several figures of the accompanying drawing.

Referring now to FIGURES 1-3, there is illustrated the preferred embodiments of a flat sandwich bag of the invention. As illustrated, thebag is formed of two flat superimposed front and rear wall members 10, 12 which are made from a thin flexible plastic film material. Both the front and rear walls 10, 12 overlie one another in a substantially flatwise manner and are joined together at the peripheral edges except at the top edge which is left open to constitute a bag mouth as indicated at 14. The bag is preferably made from a single sheet or web of the plastic film material such as a polyethylene film, for example, which is folded upon itself along a fold line at the bottom of the bag and then joined at the opposite edges suitably by heat sealing the plastic film as shown at 16, 18

As illustrated in FIGURE 3, the bag is provided with a closure flap 20 for sealing a sandwich 22 or other food product within the bag. The closure flap 20 may be formed by an extension of the rear wall 12 beyond the top of the bag a sufficient distance so that the flap 20 may be drawn down over the bag mouth 14 after the sandwich 22 has been placed within the bag, and then folded onto a substantial portion of the front wall 10 of the bag. In order to secure the closure flap 20 to the front wall 10, an adhesive is applied to the underneath side of the flap 20 preferably in the form of a continuous adhesive stripe 24 extending across the full width of the flap 20. Although the continuous adhesive stripe 24 is preferred for use in the bag, the adhesive may be provided in other forms such as a discontinuous stripe or a single adhesive patch applied to the underneath side of the flap 20. Preferably, the adhesive stripe 24 is applied in close proximity to the lower edge of the closure flap 20, leaving a free end 26 for grasping by the user when it is desired to open the bag.

The adhesive which is used to secure the closure flap 20 to the front wall of the bag is preferably of the pressure-sensitive type. With a pressure-sensitive adhesive, it is a simple matter to seal the bag by applying pressure with the users finger across the full width of the closure flap after it has been folded onto the front wall 10 of the bag.

Suitable pressure-sensitive adhesives for use in the bag include acrylic, natural and synthetic rubber and poly (vinyl ether) types. The adhesive may be applied to the closure flap 20 to a controlled thickness of approximately 0.2 mil suitably by conventional fiexographic printing techniques known in the art.

According to the novel features of the invention, the closure fiap 20 during assembly of the bag is folded upon itself to form an overfiap at the top of the bag located just above the bag mouth 14 as generally indicated at 28 in FIGURES 1 and 2. This overflap closure is formed by folding approximately the lower half of the closure fiap 20 containing the adhesive stripe 24 against the underneath side of the upper half such that the adhesive stripe 24 is completely disposed between the folded portions of the flap 20. In constructing the bag, it is preferred that the lower half of the flap 20 be made somewhat shorter in length such that the free end 26 of the fiap 20 is disposed above the bag mouth 14. In this manner, the free end 26 of the closure flap 20 is placed in a readily accessible position for grasping by the user.

By forming the folded overfiap closure of the invention, it will be seen that a protective enclosure is provided for the adhesive which is used to adhere the closure flap 20 to the front wall 10 when it is desired to close the bag. This protective enclosure protects the adhesive from coming into contact with adjacent bags when packaged within a dispensing carton and from inadvertently contacting any exterior object once the bag is removed from the carton.

Another important advantage of the invention resides in the fact that the adhesive is not exposed until the moment of use. During assembly of the bag, the adhesive is made to adhere firmly to the superimposed portion of the folded closure flap 20. With a pressure-sensitive adhesive this is easily accomplished by simply applying pressure across the folded lower half of the flap 20. Since the adhesive is completely disposed between the superimposed portions of the flap 20, it is effectively shielded from exposure to the atmosphere and is thus not subject to deterioration or loss of tenacity during the period in which the bag is stored within the dispensing carton prior to use.

FIGURE 4 shows the construction of a typical dispensing carton for flat sandwich bags embodying the invention. The carton is of rectangular shape and has an elongated dispensing slot 30 located within the top and adjacent to the front edge of the carton for withdrawal of the bags. Opposed semi-circular cutouts 32, 34 are provided within the top and front side of the carton to facilitate grasping the bags by the user. Within the carton the individual bags are stacked together one on top of the other as indicated at 36 and then folded around one edge of an acuate core 38 within the top of the carton.

When it is desired to dispense a bag from the carton, the user need only insert his two index fingers through the semi-circular cut-outs 32, 34 and grasp one bag and then withdraw the bag through the dispensing slot 30 and from the carton. Since the bag construction is such that the adhesive type closure cannot cause adjacent bags to become adhered together within the carton, there is no difficulty in dispensing one bag at a time from the carton.

To use the bag after it has been dispensed from the carton, it is a simple matter to disassemble the folded overfiap closure of the invention by pulling the free end 26 of the flap 20 upward in order to separate the adhesive 24 and to expose the full closure flap 20 for use in sealing the bag. The sandwich or other food product to be packaged is then placed within the bag and the closure flap 20 is drawn down over the bag mouth 14 and onto the front wall of the bag. Pressure is then applied by the users finger across the full width of the closure flap 20 in order to adhere the adhesive 24 to the front wall 10 and thus seal the bag.

What is claimed is:

1. A flat bag of the type used for packaging sandwiches and other food products which comprises two superimposed wall members of a thin, flexible, plastic material joined together at the peripheral edges thereof and having an open bag mouth, a closure flap extending from one wall member beyond said bag mouth and adapted to be drawn down over said bag mouth and onto the other wall member in order to seal the bag, and a pressure sensitive adhesive applied to the underneath side of said closure flap for adhering said flap to said wall member, said closure flap being folded upon itself with said adhesive disposed on one overlying superimposed portion adhering to the other superimposed portion of the folded flap completely enclosing said adhesive and protecting it from contact with an exterior object.

2. In a bag dispensing carton containing aplurality of flat plastic bags used for packaging sandwiches and other food products wherein the bags are packaged in fiatwise manner one on top of the other, the improvement in combination therewith of a fiat bag construction for each bag in the carton facilitating removal of one bag at a time from the carton, said flat bag construction comprising a bag body formed from a single sheet of thin, flexible plastic material folded upon itself to form two flat superimposed wall members, the opposite side edges of said wall members being joined together with one edge left open to constitute a bag mouth, a closure flap formed by an extension of one wall member beyond said bag mouth which is adapted to be drawn down over said bag mouth and onto the other wall member in order to seal the bag, a pressure sensitive adhesive provided on the underneath side of said closure flap in the form of a continuous adhesive strip extending across the full width of said closure flap, said continuous adhesive strip being disposed in close proximity to the lower edge of said closure flap but leaving a free end for grasping by the user, said closure flap being folded upon itself with said continuous adhesive strip disposed on one overlying superimposed portion adhering to the other superimposed portion of the folded flap completely enclosing said continuous adhesive strip and protecting it from contact with adjacent bags in the carton.

3. A fiat bag as defined by claim 1 wherein said adhesive is provided in the form of a continuous stripe applied across the full width of said closure flap.

4. A fiat bag as defined by claim 3 wherein said continuous adhesive stripe is applied in close proximity to the lower edge of said closure flap leaving a free end for grasping by the user.

References Cited UNITED STATES PATENTS 2,367,440 1/1945 Schieman 2298O 3,151,803 10/1964 Kaminski 229 3,348,762 10/1967 Kasinkas 22980 DAVID M. BOCKENEK, Primary Examiner.

US. Cl. X.R. 22962 Patent No. 3,420,433 January 7, 19E

Robert Bostwick rtified that error appears in the above identified It is ce nt are hereby corrected as patent and that said Letters Pate shown below:

In the heading to the drawing and printed specification, title of inventi: "FLAT BAG AND OVERFLAPPED ADHESIVE TAPE CLOSURE THEREFOR", each occurrence, should read FLAT BAG AND OVERFLAPPED ADHESIVE TYPE CLOSURE THEREFOR Column 1, line 63, before "dispensed" insert once Signed and sealed this 10th day of March 1970.

"(SEQ Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Commissioner of Patents Attesting Officer 

